Delivery and access to expertise is guaranteed. In other words, if some inevitable should happen to the party handling the activity, we are able to find a replacement without losing time. Thus, customers face less risk and vulnerability towards the unforeseen.
Procedures and processes are usually more effective, since they are based on years of experience.
Scaling of the activity is easy, without the expense of quality.
Customers do not need to maintain a large workforce, no need to spend time & money on recruitment or updating knowledge.
Outsourcing releases valuable time so that the customers can concentrate on their core activity.